Semi-automatic firearm magazine



FIG. 1 is a plan view of a semi-automatic firearm magazine, showing my new design;

FIG. 2 is a left elevation view thereof;

FIG. 3 is a bottom view thereof;

FIG. 4 is a front elevation view thereof;

FIG. 5 is a right elevation view thereof;

FIG. 6 is a back elevation view thereof; and,

FIG. 7 is a right perspective cross-sectional view thereof, at the arrows I-I of FIG. 5.

The broken lines in the drawings form no part of the claimed design. 

I claim, the ornamental design for semi-automatic firearm magazine, as shown and described. 